Method of making lenticular-film-embossing rollers



P. R. 0RD

May 6, 1930.

Filed Sept. 28, 1928 gwm'nto'a Perqyli. 0rd,

M I777n Firm 1;

hi Pi 4. $2

Patented May 6, 1930 UNITED STATES PATENT OFFICE PERCY R. GED, OF ROCHESTER, NEW YORK, ASSIGNOB TO EASTMAN KODAK COMPANY, .OF nocnnsrsn, new YORK, A CORPORATION OF NEW YORK METHOD OF MAKING LENTLGULAR-FILM-EMBOSSING ROLLERS Application filed September 28, 1928. Serial No. 309,028.

This invention relates to a method for making embossing rollers having a series of very .fine regularly spaced serrations adapted to press into photographic film a plurality of parallel cylindrical lenticular elements suitable ,for use with certain systems of color photography. One object of my invention is to provide a method by which a roller having the desired shape of periphery can be made. Another object is to provide a method by which very fine and accurate surfaces may be obtained in the final roller. Another ob ject of my invention is to provide a roller with a relatively hard periphery which will withstand considerable pressure,. and other objects will appear from the following specification, the novel features being particularly pointed out-in the claims at the end thereof.

In certain systems of col-or photography one side of a photographic film is provided with a plurality of lenticular elements which may be cylindrical-in shape, and which are very small; for instance, in; apreferred type of film the spacing may be .05 mm. This dimension, of course, may be varied considerably; but many event the lenticular film elements are of exceedingly small dimensions, and are, therefore, very difficultto make aceuratelyl V L 7 Coming now to the drawings wherein like reference characters throughout Fig.'3 is a top plan view of the mandrel shown in Fig. 2;

Fig. 4: is a sectional view through a holder and the coil shown in Fig. 3;

Fig. 5 is an enlarged fragmentary detail showing a step in the production of an embossing roller;

Fig. 6 1s a slmilar view of another step n producing the embossing roller; and

Fig. 7 is an enlarged fragmentary section showing a portion of the embossing roller in an exaggerated scale.

It is obviously impossible to show the wire denote like parts in any way near the proper scale, .03 to .08 mm. All of the views in the accompanying -drawings are out of proportion, and in some as shown in Fig. 1, consist of an annular memher 1 having a series of serrations or grooves 2on its outer periphery. Such a roller may be used to emboss film by having the film pressed thereon, as is well known in the art.

in order to produce successful natural color photographs the size anddimensions and particularly the radii of curvature of the resulting lenticular elements in the film must be uniform. Because of the size of these lena ticular elements the only way they can be successfully measured is under a high powered magnifying, glass of say 400 or 500 magnifications.

In accordance with my invention I provide an expanding mandrel designated broadly as 3, and consisting of a center block 4 having a bevelled periphery 5 against which an annulus 6 having an oppositely bevelled periphery 7 may be seated, and in which position said ring may be held by a clamp 8 held by a nut 9 and a screw 10 supported in the block 4. By tightening the nut 9 the extreme ends 11 of the clamp 8 press down upon the annulus 6 and hold it in the position shown in Figs. 2 to 4:. To release the mandrel, it is only necessary to unscrew nut 9, this permitfinal lenticular forming grooves 2, and may be, for example, .05 mm. This wire must be very carefully wound in place in such a manner that the wires are tangential to each other, and-in such a way that the shape of the wire is not distorted- After the. coil has been woundon the mandrel, as shown in Fig. 2, an outer coating of copper, as indicated at 13 is deposited over the copper wires,and this coating may be from three to four millimeters in thickness. After this has been done, the

required on the embossing roller the step which will nowbe described of flashing a thin plating on the inside of the wires may be omitted; but-I find that ordinarily such fine points on the resulting embossing roller are readily fractured, and it is better to reduce the thickness of this point, as indicated at Fig. 6 by depositing on the inner surface of the wires 12 a flash coating of copper 17 of,

' say, .01 mm. in thickness. This has the effect cient thickness to permit the inner surface of increasing the radii of curvature of the wires without also increasing their spacing, as can be readily seen-from Fig. 6.

With thefiashed or unfiashed wires 12 the next step consists in electro depositing a rel atively thick layer of nickel l8ion the inside ofthe wires, and this layer shouldbe of suflithereof, as shown at19, Fig. -7,to be turned down or accurately ground in a lathe so that the nickel ring 18'to form a strong support the film surface.

a supporting steel shell 20 can be pressed into for this ring.

. Thecopper material, that is, referring to Fig.6, the la er 13,'the wires 12, and the flashing 17 (i any) is then removed. This may be donesolely by etching or as much as! possible may be turned off in a lathe and the remainder etched away with acid, thus' leaving a nickel rim 18 and a steel core 20 with a series of grooves 2 in the nickel ring corresponding in number and shape to the. inner surface of the wires 12. f This, of course, produces a plurality of smooth rounded grooves 12 separated by'points'21 or ridges which are pressed into a film ordinarily under pressure while heated to some extent to slightly soften The serrations 2 will have substantially the same type surface as the wires, that is, these serrations will be smooth, and have a comparatively high polish, since the wires 12 each have a smooth polished periphery. However, since the embossing roller must besub jected to considerable pressure, it is preferable to cover the serrations with a chromium plating which is thin enough not to .destroy the contour of the serrations. This adds considerable to the strength of the nickel ring 18 serrations will result. H p

' flavingthus described my invention, what and preserves'the shape of the serrations.

The chromium layer when plated on the.

smooth surface takes the smoothness from the surface on which it is plated, so that a comparatively glossy highly finished series of the coil, removing the inside temporary s'up- I port, plating the inside of the coil, forming a hub inside of the inside plating and removing the outside plating and wire.

2. A method of making lenticular film embossing rollers comprising winding a coil of metal wire on a temporary support inside of the coil, plating the outside of the coil with the same kind ofmetal as the wire, removing the temporary support, plating the inside of the coil of wire with a different kind of metal from that of the wire support ing said last named plating on a hub member, and removing the coil of wire and the outside plating. p

3. A method of making lenticular film embossing rollers comprising winding a coil of copper wire on a' temporary support, plating the outside of the wire with copper, re-

moving the temporary support, plating the inside of the wire coil with nickel, placing a hub member inside of the nickel plating and removing the copperf'wire and copper plating from the nickel. f

, 4. A method of making lenticular film embossing rollers comprising winding a coil of copper wire on a temporary support, plating the outside of the wire with copper, removing the temporary support, plating the inside of the wire coil with a very thin layer of copper, plating this last named layer with a heavy layer of nickel, placing a hub member inside of the nickel and removing all the,

copper, that is, the plating and the wires.-

5. A method of making lenticular film embossing rollers comprising winding a coil of copper wire on a temporary support, plating the outside of the wire with copper, removing the temporary support, plating the inside-of the wire coil with nickel, placing a'hub member inside of the nickel plating and removingthe copper wire and plating with acid.

6. A method of making a lenticular. film embossing roller including winding a coil of fine copper wire on an expanding mandrel,

copper plating the exposed outside surfaces of the wire coil, removing the mandrel, de-' positing a heavy plating of nickel on the inside surfaces of the copper-wires,- facing the and plating .by etching with acid.

of fine copper wire on an expanding mandrel,

copper plating the exposed outside surfaces of the wire coil, removing the mandrel, de

positing a heavy plating of nickel on the inside of the nickel, providing a steel hub I for the nickel, and removing the copper wires.

side surfaces of the copper wires, facing the inside of the nickel,- providing a steel hub for the nickel, removing the copper wires and plating by etching with acid, and plating a thin layer of chromium on the outside surface of the nickel.

8. A method of making a lenticular film embossing roller including winding a coil of copper wire upon an expanding mandrel, electrically depositinga layer .of copper over the copper wire, removing the mandrel, in-

creasing the radius of the wires by depositing a thin layer of copper on the exposed sides thereof, depositing a comparatively thick layer of nickel on the co per, and finish ing the inner surface thereo true, attaching an inner hub member to the'nickel, etching away the 'copper,-and electrodepositing a thin chromium layer over the nickel, whereby a c linder having a face complementary to that of the inner contour of the wires will result.

9. Amethod of making a lenticular film 7 embossing roller includingwinding a coil of copper wire of approximately .05 mm. in diameter upon an expanding mandrel, elec trically depositing a layer of copper. over the copper Wire, removing the mandrel, increasing the radius of the wires by depositing a thinlayer of copper on the exposed sides thereof, depositing a comparatively thick layer of nickel on the copper, and finishing the'inner surface thereof true, attaching an inner hub member to the nickel, etching away the copper, and electrodepositing a thin chromium layer over thenickel, whereby a cylinder having a series of grooves spaced .05 mm-.apart will result.

Signed at Rochester, New York this 25th day of September, 1928.

' g I PERCY R. ORD. 

